Traditional and novel fermented foods and beverages from tropical root and tuber crops: review

Tropical root and tuber crops [cassava, sweet potato, yams, colocasia (taro), etc] are important staples for food security for about a fifth of the world population. Bulk of cassava in Africa and Latin America are processed into fermented foods and food additives such as organic (acetic, citric and lactic) acids, mono-sodium glutamate, etc. The fermented foods from cassava are gari , fufu , lafun , chickwanghe , agbelima , attieke and kivunde in Africa, tape in Asia and ' cheese ' bread , and ' coated peanut ' in Latin America. Lactic acid bacteria and yeasts are the major group of micro-organisms associated with cassava fermentation. Similarly, sweet potatoes can be fermented into soy sauce, vinegar, lacto-juices, lacto-pickles and sochu (an alcoholic drink produced in Japan), and yams into fermented flour. Most of these fermented food products are functional foods rich in phytochemicals, dietary fibres, anti-oxidant compounds (β-carotene, anthocyanin, etc) and probiotic components (lactic acid bacteria and yeasts).